Although fungi are responsible for a number of serious disease conditions, they often parasitize humans without causing overt symptoms of disease. For example, the fungus Candida albicans is commonly found among the flora inhabiting the skin, mouth, and intestinal tract of a human. When fungi do produce detectable disease in otherwise healthy individuals, they usually cause mild infections such as athlete's foot, a topical fungal infection.
Individuals whose immune systems are compromised, however, are at much greater risk for contracting serious fungal infections. The normally harmless fungus Candida albicans, for example, is an opportunistic pathogen and can cause serious disease in immunocompromised patients. People who take immunosuppresive medication or who suffer from AIDS, therefore, are particularly susceptible to opportunistic fungal infections.
Heretofore, in order to diagnose a fungal infection, a diagnostician must have first observed symptoms or suspected other reasons in a patient that indicate that the patient might be suffering from a fungal infection. The presence of a fungal pathogenic agent and the identification of a particular species of fungus responsible for causing such symptoms can generally only be confirmed by taking a biological sample from the patient and culturing the sample. After a period of time, the culture is visually observed, and if a fungus grows in the culture in numbers sufficient to indicate a fungal infection, that fungus is identified by observing its morphological characteristics.